Preheat your oven to 325°F (160°C).
In a large bowl, combine flour, sugar, baking powder, and salt.
In another bowl, mix egg yolks, vegetable oil, water, and vanilla extract until smooth.
Add the wet ingredients to the dry ingredients and mix until combined.
In a separate bowl, beat egg whites with cream of tartar until stiff peaks form.
Gently fold the egg whites into the batter.
Pour the batter into an ungreased tube pan.
Bake for 50-60 minutes or until a toothpick comes out clean.
Remove from the oven and invert the pan to cool completely.
Once cooled, run a knife around the edges and remove the cake from the pan.